Problems when a late scratching

[The A Train]

Is there a rule that I can put in to cancel all bets if there is a late scratching. I have auto lays going into the market and if a horse gets scratched at the gate it can play havoc with the odds on the remaining horses.

[Euler]

You can use signals to mark the number of runners then use that as a condition when a bet goes in.

If it's really late and Betfair don't remove it from the market then you can't trap that unless you see it with your own eyes.

[The A Train]

Thanks for the assist